She said: “It beggars belief that someone could be so heartless as to dump small kittens like this.

Anyone with information should contact the RSPCA inspectorate appeal line on 0300 123 8018.

The RSPCA said all calls would be treated in confidence. To help the RSPCA investigate cases like this, the public have been asked to help by giving £3 by texting HELP to 78866. Text costs £3 and one standard network rate message.